1. Field of the Invention
The present invention relates to a chip-like electronic component and a method of manufacturing the same. More particularly, the present invention relates to an improvement in forming external electrodes in a chip-like electronic component.
2. Description of the Related Art
FIG. 11 is a perspective view schematically showing an outer appearance of a chip-like electronic component 1, on the basis of which the present invention has been developed. A chip-like electronic component having three terminals and having an outer appearance as shown in FIG. 11 has been known. This type of an electronic component includes, for example, a chip-like coil, a three-terminal capacitor, a capacitor array, an LC filter and a capacitor network.
The chip-like electronic component 1 includes an element main body 2. Such an element main body 2 includes a first end surface 3 and a second end surface 4 on the opposite end of the main body 2. The element main body 2 further includes a first side surface 5, a second side surface 6, a third side surface 7 and a fourth side surface 8, all of which are connected to the first end surface 3 and the second end surface 4.
Further, on the outer surface of the element main body 2 a first external electrode 9, a second external electrode 10 and a third external electrode 11 are provided. The first external electrode 9, the second external electrode 10 and the third external electrode 11 are arranged such that they surround the first side surface 5, the second side surface 6, the third side surface 7 and the fourth side surface 8.
The first external electrode 9 is positioned on the first end surface 3 of the element main body 2, and is arranged such that the first end surface 3 is entirely covered by the first external electrode 9. The second external electrode 10 is positioned on the second end surface 4 of the element main body 2, and is configured such that the second end surface 4 is entirely covered by the second external electrode 10. Further, the third external electrode 11 is positioned between the first external electrode 9 and the second external electrode 10.
The above described external electrodes 9 to 11 are formed by applying an electrically conductive paste on the element main body 2, drying and sintering the applied paste. However, a method of applying the electrically conductive paste for defining the external electrodes 9 to 11 may be carried out in the following way.
First, a process for forming the first external electrode 9 may be conducted in a manner shown in FIG. 12. An electrically conductive paste layer 13 having a desired thickness is formed in a dip tray 12. Then, a main body 2 is dipped into the electrically conductive paste layer 13, moved in a direction shown by an arrow 14, with the first end surface 3 facing downwardly towards the electrically conductive paste layer 13, followed by moving the element main body 2 upwardly away from the paste layer 13. In this way, the electrically conductive paste 13 may be applied to the first end surface 3 of the element main body 2, and to a portion of each of the adjacent side surfaces 5 to 8, so as to form the first external electrode 9.
Next, an operation similar to that described above is carried out on the second end surface 4 of the element main body 2. In this way, the electrically conductive paste 13 may be applied to the second end surface 4 of the element main body 2, and to a portion of each of the adjacent side surfaces 5 to 8, so as to form the second external electrode 10.
Subsequently, in order to form the third external electrode 11, a process shown in FIG. 13 is carried out. In this process, a slit plate 15 is used. Such a slit plate 15 is provided with a plurality of slits 16 each having a width corresponding to the width of the third external electrode 11. The slit plate 15 is disposed so as to close an upper opening of a paste tank 17 containing an amount of an electrically conductive paste 13. Moreover, a cylinder 18 is arranged to communicate with the internal space of the paste tank 17. A piston 19 is provided within the cylinder 18.
A plurality of element main bodies 2 are arranged such that the first side surface 5 of each element main body comes into contact with the slit plate 15. Then, the piston 19 is displaced in a direction shown by an arrow 20, so that the electrically conductive paste 13 flows through the plurality of the slits 16 so as to be supplied to the upper surface of the slit plate 15. As a result, the electrically conductive paste 13 may be applied to the middle (in the longitudinal direction) of the first side surface 5 of each element main body 2.
Similar operations are then carried out successively on the second to fourth side surfaces 6 to 8 of each element main body 2.
Additionally, rather than using a process shown in FIG. 13, a process shown in FIG. 14 may also be used. In the process shown in FIG. 14, a paste application plate 21 is used and is formed of an elastomeric material capable of elastically deforming in a manner similar to rubber. The paste applying plate 21 is provided with a plurality of grooves each having a width corresponding to the width of the third external electrode 11. Each of the grooves 22 is filled with the electrically conductive paste 13.
Then, each element main body 2 is pressed on the paste applying plate 21 with its first side surface 5 in contact with the paste applying plate 21. In this way, each element main body 2 will cause the paste applying plate 21 to be compressed so as to deform in its thickness direction. As a result, the electrically conductive paste 13 contained in each groove 22 is applied to the middle (in the longitudinal direction) of the first side surface 5 of each element main body 2.
Similar operations are then carried out successively on the second to fourth side surfaces 6 to 8 of each element main body 2.
However, in order to manufacture the chip-like electronic component shown in FIG. 11, because it is necessary to form the first, second and third electronic electrodes 9, 10 and 11 on the element main body 2, it is necessary to carry out several different processes as shown in FIG. 12 and FIG. 13 or FIG. 14. Further, because the process shown in FIG. 12 has to be carried out successively on the first and second end surfaces 3 and 4, i.e., because the same process has to be carried out twice, the entire production process of manufacturing the chip-like electronic component is excessively complicated. Moreover, since the process shown in FIG. 13 or the process shown in FIG. 14 has to be carried out on the first to fourth side surfaces 5 to 8, the same process has to be carried out four times in total, hence making the entire production process of manufacturing the chip-like electronic component excessively complex.
In view of the above, because many steps are required in applying the electrically conductive paste to an element main body to produce the external electrodes 9 to 11, the production cost for manufacturing the chip-like electronic component 1 is excessively high. For this reason, there has been a demand to reduce the number of steps in applying the electrically conductive paste 13.
In order to overcome the above-described problems, preferred embodiments of the present invention provide an improved chip-like electronic component and an improved method of manufacturing the same.
Preferred embodiments of the present invention improve the external electrodes of a chip-like electronic component, thereby solving the above discussed problems.
Preferred embodiments of the present invention provide a chip-like electronic component including a chip-like element main body having a first end surface and a second end surface which are opposite to each other, a first side surface, a second side surface, a third side surface and a fourth side surface, all of which are connected between the first end surface and the second end surface, external electrodes provided on the outer surface of the chip-like element main body, wherein the external electrodes are provided on at least the first side surface, the external electrodes including a first external electrode provided on the first end surface side, a second external electrode provided on the second end surface side, a third external electrode provided between the first external electrode and the second external electrode. The chip-like electronic component of preferred embodiments of the present invention includes the following arrangement.
The first external electrode, the second external electrode and the third external electrode are arranged to extend to other surfaces adjacent to the first side surface, the first external electrode and the second external electrode are configured such that the first end surface and the second end surface are exposed at least at approximate central portions thereof.
With the chip-like electronic component of preferred embodiments of the present invention, areas for the external electrodes to be provided on an element main body may be optionally changed. The external electrodes may also be provided only on the first side surface, or further on the third side surface opposite to the first side surface. Moreover, the external electrodes may be provided on the second side surface and on the fourth side surface. In this way, the external electrodes extend around the first, second, third and fourth side surfaces.
Further, aspects of preferred embodiments of the present invention may be employed in various types of chip-like electronic components. For example, preferred embodiments of the present invention are directed to an LC composite electronic component including a chip-like element main body includes a first inductor and a second inductor which are connected in series with each other between the first external electrode and the second external electrode, further including a capacitor having one capacitor electrode connected to the third external electrode and another capacitor electrode connected to an approximate middle point between the first inductor and the second inductor.
Moreover, when the chip-like electronic component according to preferred embodiments of the present invention is an LC composite electronic component as described above, it preferably has the following configuration.
The chip-like element main body has a laminated structure provided by a plurality of electrically insulating layers laminated in the longitudinal direction of the element main body so as to connect between the first end surface and the second end surface. The first inductor is disposed in the vicinity of the first end surface, which is located in a one third portion of the chip-like element main body in the longitudinal direction, the second inductor is disposed in the vicinity of the second end surface, the capacitor is disposed in an approximate central portion of the chip-like element main body.
The first inductor and the second inductor are provided by coil conductors arranged among the electrically insulating layers and via-hole conductors provided through the electrically insulating layers, such that the two inductors extend in a coiled configuration with the axial direction thereof being coincident with the longitudinal direction of the chip-like element main body. The capacitor electrodes constituting the capacitor are provided among the electrically insulating layers.
Additionally, other preferred embodiments of the present invention are directed to a method of manufacturing a chip-like electronic component described above. The manufacturing method includes the following processes.
First, a plurality of element main bodies is prepared.
Then, a slit plate having a first main surface and a second main surface which are opposite to each other with a predetermined interval therebetween is provided, and having first, second and third slits capable of passing an electrically conductive paste so as to apply the paste to any of the side surfaces of each element main body to form a first external electrode, a second external electrode and a third external electrode on each element main body. The application of the paste being performed under a condition in which each element main body is placed on to the slit plate such that any one of the first to fourth side surfaces of an element main body is in contact with the first main surface of the slit plate.
Subsequently, a step of placing each element main body on the first main surface of the slit plate such that any one of the side surfaces of each element main body surfaces the first main surface of the slit plate is performed.
Afterwards, a step of supplying the electrically conductive paste so as to flow through the first, second and third slits to the first main surface of the slit plate, so as to apply the electrically conductive paste to any one of the side surfaces of each element main body is performed.
More particularly, the method of manufacturing a chip-like electronic component according to preferred embodiments of the present invention is carried out in the following way.
The step of preparing the slit plate includes placing a closing plate having a resilient member which is capable of contacting the second main surface of the slit plate so as to close the first, second and third slits, preparing a pressing plate capable of pressing the closing plate so as to cause the closing plate to elastically deform towards the first, second and third slits, and filling the first, second and third slits with the electrically conductive paste. Further, the step of applying the electrically conductive paste includes pressing the closing plate by the pressing plate, so as to cause the closing plate to elastically deform towards the first, second and third slits, thereby causing the electrically conductive paste filled in the first, second and third slits to flow onto the first main surface of the slit plate, thus enabling the electrically conductive paste in the first, second and third slits to be applied to any one of the side surfaces of each element main body.
Other features, characteristics, elements and advantages of the present invention will become apparent from the following description of preferred embodiments thereof with reference to the attached drawings.